Means for altering the clearance in internal-combustion engines



T. a. TULLOCH. MEANS FOR ALTERING THE CLEARANCE IN INTERNAL COMBUSTION ENGINES.

APPLICATION FI'LED FEB. 25, I921- Patented Dec. 12, 1922.

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Patented l2 M9223 THOMAS TULLOCH, OF LONDON ENG-LAND, 'ASSIGNOR, BY llZESNE ASEGN- IEEN'I'S, TO AUTGMOTIVE GAS PRGDUGER CORPORATION, A CORPORATION 03? DELA- l/VAPJE.

FOR ALTEPJING THE CLEARZHTCE IN INTIEENAL-CQMBUSTION EhTGrINfi-E.

Application filed February 25, 1921. Serial No. 447,?97.

To il /1,07% may concern:

Be it known that l THOMAS Gnncomn Turmoorr, a subject of the King oi? Great Britain, residing at Bank Buildings. St. James Street, in the county of London, England. have invented certain new and useful Improvements in or Relatingto Means for Altering the Clearance in II rnal-Combustion Engines of which the following a specification. Y

This invention relates to means for alteringthe clearance in internal comlnistion engines which are adapted to use liquid *luel and has for its chiei object to provide a device which enables existing engines of that kind to be efiiciently utilized for gaseous fuel, more particularly producer If an engine of the ordinary petrol tnve, such as that employed on motor vehicles, is to serve for gaseous fuel it is desirable that the compression should be substantially increased the compression of an ordinary petrol enpine amounting to say, 60 to lbs, while the compression desirable for gaseous "Fuel would be about 120 to M0 lbs.

According; to this invention. to ad ct engine constructed foruse with liquid fuel. for the utilization of gaseous fuel such as producer I reduce the compression space in the cylinder bv any suitable method. such as dominothe piston, and fit to the cylinder an auxiliary chamber adapted to be opened to or cut of? from the compression space oi the cylinder. When the ene'ine is running; on gaseous fuel the auxiliary chamber is cut off and the reduced compression space is employed, so that the compression pressure is raised to the higher level desirable. Also on starting the engine it is desirable that tie compression pressure should be low and there ore the auxili chamber may then be opened to the cylinder and cut oil when the engine has properly started. It liquid fuel is to be utilized the auxiliary chamber is opened to the cylinder aud allows of the reduced compression pressure found preferable.

In order that the said invention may be clearly understood and readily carried into effect the same will now be more full;- described with reference to the accompanying drawing which shows diagrammatically in elevation a cylinder provided with. the auxiliary chamber in accordance with this invention. y

A is the cylinder. B is the piston. the head of which is domed as shown at 7). is the auxiliary chamber mounted on the top or head of the cylinder and D is a valve or cook by which the chamber C may be connected up to the working space of the cylinder or out off as required.

The auxiliary chamber C as shown. be in the form of a small cylinder secured on a stem 0 adanted to be screwed into a tapped hole in the top a of the cylinder A the stem carrying the valve or tap D with a lever or handle (Z or other operating device under the control of the driver. adapted to open the auxiliary cylinder A. on starting the engine and to cut it on when the hi her compression nressure is requ i'red. A release tan 0 is fitted to the chamber C, which enables the products of combustion in the chamber to escape after closing the cool: or valve D and also provides means for allowing a detergent fluid to be inserted into the chamber so that when the precincts of combustion are permitted toescape. they will carry any deleterited in the 01 matter they may have colle chamber.

in altering an existing encrine. for example, the engine of motor lorry or other heavy motor vehicle. the ordinary pistons are removed and renlaced by a setof domed pistons such as s indicated at B in the diaorann or the cylinders may be the crank case or space re ucinp; members be fitted inside the cylinders to bring the compression space down to the required volume. The auxiliary chamber C may be fitted in placeoi the existing compression tap or may be separately vtitted to any convenient part of the upper end of the cylinder. All the valves controlling} the communication between the auxiliary chambers and the cylinders of a multi-cylinder engine chamber C to the lowered upon connected "from the compression space in said cylinder so as to permit of different degrees of compression therein, and means 10 connected to said chamber to allow the pro ducts of combustion to escape therefrom.

THOMAS GREGORIE TULLOCH. 

